U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications

NIST Authors in Bold

Displaying 476 - 500 of 1719

PDH-locked, frequency-stabilized cavity ring-down spectrometer

June 16, 2011
Author(s)
Joseph T. Hodges, A. Cygan, Piotr Maslowski, Katarzyna E. Bielska, S. Wojtewicz, J. Domyslawska, Hisashi Abe, R.S. Trawinski, R. Ciurylo
We describe a high sensitivity and high spectral resolution laser absorption spectrometer based upon the frequency-stabilized cavity ring-down spectroscopy (FS-CRDS) technique. We used the Pound-Drever-Hall (PDH) method to lock the probe laser to the high

Controlled Vapor Deposition Approach to Generating Surface Energy/Chemistry Gradients

June 9, 2011
Author(s)
Julie N. Albert, Joey D. Kim, Christopher Stafford, Thomas H. Epps
Substrate surface energy/chemistry gradients provide a means for high-throughput exploration of the surface interactions that are important for many chemical and biological processes. We describe the implementation of a controlled vapor deposition approach

Combinatorial and High-throughput Screening of Biomaterials

June 6, 2011
Author(s)
Carl Simon Jr., Sheng Lin-Gibson
The review describes recent advances in utilizing combinatorial and high-throughput methods to better understand cell-material interactions, in terms of cell toxicity, adhesion, morphology, migration, proliferation and differentiation, particularly

Imaging Cells in Polymer Scaffolds by X-Ray Microcomputed Tomography

May 11, 2011
Author(s)
Shauna M. Dorsey, Sheng Lin-Gibson, Carl Simon Jr.
We have investigated the ability of X-ray microcomputed tomography (CT) to make quantitative, three-dimensional (3D) measurements of cell adhesion and proliferation in polymeric tissue engineering scaffolds. The most common method for examining cells in

Combinatorial Screening of Hydrogel Scaffolds for 3D Cell Culture

May 2, 2011
Author(s)
Kaushik Chatterjee, Marian F. Young, Carl Simon Jr.
Optimizing cell-material interactions is critical towards maximizing regeneration in tissue engineering. Combinatorial and high-throughput (CHT) methods can be used to systematically screen tissue scaffolds to identify optimal biomaterial properties

NIST Reference Material Scaffolds Characterized for Cell Response

April 24, 2011
Author(s)
Carl G. Simon Jr., Jeff M. Coles
Reference scaffolds characterized for cell response are being developed for use as a standard for biological characterization of new scaffolds. The need for reference scaffolds to serve as a calibration standard between labs has been identified as critical

Modulus-Driven Differentiation of Marrow Stromal Cells in 3D Is Independent of Cytoskeletal Integrity

April 11, 2011
Author(s)
Carl G. Simon Jr., Kaushik Chatterjee, Sapun Parekh, Sheng Lin-Gibson, Nicole M. Moore, Marcus T. Cicerone, Marian F. Young
Cell functions such as proliferation, migration, and differentiation are key physiological processes that are influenced by the physiochemical extracellular environment. We report on the effect of three-dimensional (3D) scaffold modulus on human bone

CONTINUOUS FLOW ENZYME-CATALYZED POLYMERIZATION IN A MICROREACTOR

March 25, 2011
Author(s)
Santanu S. Kundu, Atul S. Bhangale, William E. Wallace, Kathleen M. Flynn, Charles M. Guttman, Richard Gross, Kathryn L. Beers
Enzymes immobilized on solid supports are increasingly used for chemical transformation because the process is greener and sustainable. Here we use microreactors to study enzyme catalyzed ring opening polymerization of -caprolactone to polycaprolactone. A

Effect of interfaces and adhesion on the creep compliance of thin polymer coatings

February 13, 2011
Author(s)
Peter M. Johnson, John A. Howarter, Christopher Stafford
Thin film indentation experiments on viscoelastic materials allowed for the deconvolution of the bulk compliance from interfacial responses at the buried interface. This technique could discriminate both large changes in the interfacial strength due to

Manipulation of adhesion via sub-surface patterning

February 13, 2011
Author(s)
John A. Howarter, Peter M. Johnson, Jun Y. Chung, Christopher Stafford
The delamination characteristics of patterned and hierarchical interfaces are of great interest due to the advanced adhesion capabilities found with many biological surfaces. Using nature-inspired design principles, micro- and nanostrucutred surfaces have

OCT For Depth Detection of Buried Particles in Polymeric Materials

February 13, 2011
Author(s)
Robert C. Chang, Anant Agrawal, Peter M. Johnson, Christopher Stafford
In this work, we demonstrate a method to produce novel optical phantoms usable for the characterization of OCT axial resolution and contrast. By varying the diameter of the microspheres and the thickness of the polymer layers, different spatial frequencies

In situ Formation of Silver Nanoparticles in Photocrosslinking Polymers

February 2, 2011
Author(s)
Yajun Cheng, Diana N. Zeiger, John A. Howarter, Xinran Zhang, Nancy Lin, Joseph M. Antonucci, Sheng Lin-Gibson
Nanocomposites of difunctional methacrylate polymer/silver nanoparticles have been synthesized by coupling photoinitiated free radical polymerization with in situ silver ion reduction. A polymerizable methacrylate bearing a secondary amino function group

Controlled in situ Nanocavitation in Polymeric Materials

January 18, 2011
Author(s)
Yajun Cheng, Joseph M. Antonucci, Steven Hudson, Nancy Lin, Xinran Zhang, Sheng Lin-Gibson
A new strategy to produce polymer-inorganic composites with ultra low volume shrinkage has been developed. Small amount of cavitation agent, acetone dicarboxylic acid (ADCA), was introduced into acrylate-glass composites and decomposed in situ to carbon

Influence of substrate on crystallization in polythiophene/fullerene blends

January 13, 2011
Author(s)
Lee J. Richter, Christine He, David Germack, R Joseph Kline, Dean DeLongchamp, Daniel A. Fischer, Chad R. Snyder, James G. Kushmerick
The nanoscale morphology of the active layer in organic, bulk heterojunction (BHJ) solar cells is crucial to device performance. Often a combination of casting conditions and post deposition thermal treatment are used to optimize the morphology. In general

Comment on Viscoelastic properties of con ned polymer lms measured via thermal wrinkling by Edwin P. Chan, Kirt A. Page, Se Hyuk Im, Derek L. Patton, Rui Huang and Christopher M. Stafford, Soft Matter (Communications), 5, 4638 4641 (2009).

January 11, 2011
Author(s)
Paul A. O'Connell, Greg B. McKenna, Edwin Chan, Christopher Stafford
Recently Chan et al. published a paper describing a method to use the wrinkling of a thin elastic film on which is adhered a thin polymer film to extract the viscoelastic properties of the polymer. Results were presented for the rubbery plateau modulus and
Displaying 476 - 500 of 1719